Portable programmable calculator

ABSTRACT

Two battery-powered hand-held programmable calculators for performing arithmetic, trigonometric and logarithmic functions and displaying the results thereof are provided with the capability of being fully programmable via magnetic cards or a keyboard. Through a unique transmographic coding scheme, programs coded on one embodiment may be executed on a second embodiment even though the key codes for the respective functions are dissimilar. In one embodiment, a processor distinguishes between magnetic cards containing coded instructions and cards containing data. The calculator prompts the user via the display when additional cards are needed to form a complete set of program instructions. The processor, registers, and display may be initialized by control words on magnetic cards. During program execution, the calculator can pause to permit data entry from the keyboard or from magnetic cards. The operator may also cause the calculator to pause and display the data of an intermediate calculation. A number of stack and program review capabilities are provided, including the ability to accelerate, temporarily suspend, or indefinitely suspend review. The operator may select either of two sets of registers for access by the processor. In one embodiment, a hard copy printer is provided for creating a permanent record of the calculations.



